Comparison of dose standard units for drug utilisation studies

Analysis of biosimilars consumption in an Italian Local Health Authority

Biosimilar drugs offer an opportunity for all global healthcare systems because they provide significant cost savings while ensuring equal efficacy and safety in the treatment of chronic diseases. These savings can be allocated to support ongoing innovation. An analysis of the usage of major biosimilar drugs across various therapeutic areas has been conducted within an Italian healthcare company serving a population of over one million. Data on consumption, expenditure, and the number of treated patients has been extracted from the company's databases. Finally, a comparison with the year 2021 has been performed to determine if biosimilar drug usage increased in 2022. In 2022, the data reveals that a substantial portion of the analysed active ingredients are being used as biosimilar drugs, except in a few residual cases. However, among the most consumed drugs, resistance still exists in the case of Adalimumab and Etanercept, for which expenditure on originator drugs exceeds 2 million euros. The 2022-2021 comparison highlights the increasing use of biosimilar drugs. This data is encouraging and suggests that in the coming months, we may achieve total utilization, which would be to the benefit of the National Healthcare System (NHS) and the citizens who can rely on an efficient and sustainable healthcare policy that is continually improving.

The impact of clinical inertia on uncontrolled blood pressure in treated hypertension: real-world, longitudinal data from Japan

We aimed to quantify the impact of inadequate pharmacological therapy on uncontrolled blood pressure (BP) using Japanese real-world data. This retrospective cohort study used databases provided by DeSC Healthcare, Inc (Tokyo, Japan). We identified 27,652 patients with hypertension (age, 60.7 ± 9.1 years; men, 56.4%) who were not receiving antihypertensive treatment at the initial visit (pre-treatment) and were under treatment at the next visit (post-treatment). Patients were classified into the following groups by the number of antihypertensive drug classes and defined daily dose (DDD): one antihypertensive drug class with a low dose (DDD < 1.0), one antihypertensive drug class with a moderate-to-high dose (DDD ≥ 1.0), two antihypertensive drug classes with a low dose (DDD < 2.0), two antihypertensive drug classes with a moderate-to-high dose (DDD ≥ 2.0), and ≥three antihypertensive drug classes. The pre-treatment systolic/diastolic BP was 157.7 ± 15.4/94.2 ± 11.5 mmHg. Overall, 43.0% of patients had uncontrolled BP (post-treatment BP ≥ 140/ ≥ 90 mmHg). High pre-treatment BP was a strong factor for uncontrolled BP. After adjustments for covariates, including the pre-treatment mean BP, the proportion of patients with uncontrolled BP was 2.08 times higher in the one antihypertensive drug class with a low dose group than in the ≥three antihypertensive drug classes group. The preventable fraction due to Collapse

Key Words

• Blood pressure
• Clinical inertia
• Cohort study
• Epidemiology

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MESH Headings

• Male
• Humans
• Middle Aged
• Aged
• Antihypertensive Agents/adverse effects
• Blood Pressure
• Japan
• Retrospective Studies
• Hypertension/drug therapy
• Hypertension/chemically induced

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Affiliation(s)

Michihiro Satoh Division of Public Health, Hygiene and Epidemiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan. Department of Preventive Medicine and Epidemiology, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan. Department of Pharmacy, Tohoku Medical and Pharmaceutical University Hospital, Sendai, Japan.
Tomoko Muroya Division of Public Health, Hygiene and Epidemiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan Division of Internal Medicine, Izumi Hospital, Sendai, Japan
Takahisa Murakami Division of Public Health, Hygiene and Epidemiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan Department of Preventive Medicine and Epidemiology, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan Division of Aging and Geriatric Dentistry, Department of Rehabilitation Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan
Taku Obara Department of Preventive Medicine and Epidemiology, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai, Japan
Kei Asayama Department of Hygiene and Public Health, Teikyo University School of Medicine, Tokyo, Japan Tohoku Institute for Management of Blood Pressure, Sendai, Japan
Takayoshi Ohkubo Department of Hygiene and Public Health, Teikyo University School of Medicine, Tokyo, Japan Tohoku Institute for Management of Blood Pressure, Sendai, Japan
Yutaka Imai Tohoku Institute for Management of Blood Pressure, Sendai, Japan
Hirohito Metoki Division of Public Health, Hygiene and Epidemiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan Department of Preventive Medicine and Epidemiology, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan Tohoku Institute for Management of Blood Pressure, Sendai, Japan

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Treatment patterns in essential tremor: Real-world evidence from a United Kingdom and France primary care database

BACKGROUND AND PURPOSE

Essential tremor (ET) is one of the most common neurological disorders, but information on treatment pattern is still scant. The aim of this study was to describe the demographic and clinical characteristics, treatment patterns, and determinants of drug use in patients with newly diagnosed ET in France and the United Kingdom.

METHODS

Incident cases of ET diagnosed between January 1, 2015 and December 31, 2018 with 2 years of follow-up were identified by using The Health Improvement Network (THIN®) general practice database. During the follow-up, we assessed the daily prevalence of use and potential switches from first-line to second-line treatment or other lines of treatment. Logistic regression models were conducted to assess the effect of demographic and clinical characteristics on the likelihood of receiving ET treatment.

RESULTS

A total of 2957 and 3249 patients were selected in the United Kingdom and France, respectively. Among ET patients, drug use increased from 12 months to 1 month prior the date of index diagnosis (ID). After ID, nearly 40% of patients received at least one ET treatment, but during follow-up drug use decreased and at the end of the follow-up approximately 20% of patients were still on treatment. Among treated patients, ≤10% maintained the same treatment throughout the entire follow-up, nearly 20% switched, and 40%-75% interrupted any treatment. Results from the multivariate analysis revealed that, both in France and the United Kingdom, patients receiving multiple concomitant therapies and affected by psychiatric conditions were more likely to receive an ET medication.

CONCLUSION

This study shows that ET is an undertreated disease with a lower-than-expected number of patients receiving and maintaining pharmacological treatment. Misclassification of ET diagnosis should be acknowledged; thus, results require cautious interpretation.

Prescribed daily-dose-based metrics of oral antibiotic use for hospitalized children in Japan

OBJECTIVE

Defined daily-dose (DDD)-based metrics are frequently used to measure antibiotic consumption. However, they are unsuitable for the pediatric population because they are defined using the maintenance dose for 70-kg adults. Moreover, children have large body weight variations. We assessed the prescribed daily dose (PDD) and PDD-based metrics of oral antibiotics for children to develop an alternative to DDD-based metrics in Japan.

DESIGN

We performed observational study using data from the Japanese administrative claims database between April 2018 and March 2019.

METHODS

Of 453,001 patients (aged 1 month-15 years), 564,326 admissions to 1,159 hospitals were included. We showed the median PDD (mg/day and mg/kg/day) and PDD-based metrics for 8 antibiotics for each age category (1 month to <1 year old and 1-6, 7-12, and 13-15 years old). We also assessed the relationship between PDD-based metrics and days of therapy (DOT)-based metrics using a scatter plot and correlation.

RESULTS

In total, 86,389 patients (19.1%) were prescribed oral antibiotics; amoxicillin, macrolides, and third-generation cephalosporins were the most common. The PDD (mg/day) for each antibiotic increased with age to 7-12 years old, when an adult dose was reached. The PDD (mg/kg/day) decreased with age to 13-15 years old, due to increasing body weight. The relationship between PDD per 1,000 patient days and DOT per 1,000 patient days differed depending on the antibiotic.

CONCLUSIONS

PDD-based metrics stratified by age could characterize antibiotic consumption, even with body-weight variations. Therefore, PDD-based metrics, in addition to DOT-based metrics, are helpful benchmarks for antibiotic use in children.

An Updated Analysis of Psychotropic Medicine Utilisation in Older People in New Zealand from 2005 to 2019

BACKGROUND

Psychotropic medicine utilisation in older adults continues to be of interest because of overuse and concerns surrounding its safety and efficacy.

OBJECTIVE

This study aimed to characterise the utilisation of psychotropic medicines in older people in New Zealand.

METHODS

We conducted a repeated cross-sectional analysis of national dispensing data from 1 January, 2005 to 31 December, 2019. We defined utilisation using the Anatomical Therapeutic Chemical classification defined daily dose system. Utilisation was measured in terms of the defined daily dose (DDD) per 1000 older people per day (TOPD).

RESULTS

Overall, the utilisation of psychotropic medicines increased marginally by 0.42% between 2005 and 2019. The utilisation increased for antidepressants (72.42 to 75.21 DDD/TOPD) and antipsychotics (6.06-19.04 DDD/TOPD). In contrast, the utilisation of hypnotics and sedatives (53.74-38.90 DDD/TOPD) and anxiolytics decreased (10.20-9.87 DDD/TOPD). The utilisation of atypical antipsychotics increased (4.06-18.72 DDD/TOPD), with the highest percentage change in DDD/TOPD contributed by olanzapine (520.6 %). In comparison, utilisation of typical antipsychotics was relatively stable (2.00-2.06 DDD/TOPD). The utilisation of venlafaxine increased remarkably by 5.7 times between 2005 and 2019. The utilisation of zopiclone was far greater than that of other hypnotics in 2019.

CONCLUSIONS

There was only a marginal increase in psychotropic medicines utilisation from 2005 to 2019 in older adults in New Zealand. There was a five-fold increase in the utilisation of antipsychotic medicines. Continued monitoring of psychotropic medicine utilisation will be of interest to understand the utilisation of antidepressants and antipsychotic medicines during the coronavirus disease 2019 pandemic year.

Short-term, but not long-term, beneficial effects of concomitant benzodiazepine use on clinical course in patients with schizophrenia

This study aims to examine possible differences in the effect on the course characteristics of the disease in cases of no use, short-term use and long-term use of benzodiazepines in patients with schizophrenia. In this retrospective observational study, the sample comprised patients with schizophrenia who were admitted to our psychiatric clinics from January 2015 to January 2019. Patients were also retrospectively tracked from the date of the first admission during the specified time until the end of the observation period (24 months) for clinical course characteristics. Data for 1710 patients with schizophrenia were included in the analyses. Patients with short-term benzodiazepines use had fewer psychiatric hospitalizations and shorter lengths of stay at psychiatric services than patients with no use or long-term use. Rates of antipsychotic drug discontinuation and suicidal behavior were also significantly lower among short-term benzodiazepines users than among those with no use or long-term use. In conclusion, our study indicates that short-term benzodiazepines use is associated with a better clinical course in patients with schizophrenia. Future studies should evaluate the effects of different benzodiazepines use patterns on disease prognosis with longer-term follow-up and prospective methodology and should concomitantly examine psychopathological variables.

The Random Effects Warfarin Days' Supply (REWarDS) Model: Development and Validation of a Novel Method for Estimating Exposure to Warfarin Using Administrative Data

Warfarin's complex dosing is a significant barrier to measurement of its exposure in observational studies using population databases. Using population-based administrative data (1996-2019) from British Columbia, Canada, we developed a method based on statistical modeling (Random Effects Warfarin Days' Supply (REWarDS)) that involves fitting a random-effects linear regression model to patients' cumulative dosage over time for estimation of warfarin exposure. Model parameters included a minimal universally available set of variables from prescription records for estimation of patients' individualized average daily doses of warfarin. REWarDS estimates were validated against a reference standard (manual calculation of the daily dose using the free-text administration instructions entered by the dispensing pharmacist) and compared with alternative methods (fixed window, fixed tablet, defined daily dose, and reverse wait time distribution) using Pearson's correlation coefficient (r), the intraclass correlation coefficient, and the root mean squared error. REWarDS-estimated days' supply showed strong correlation and agreement with the reference standard (r = 0.90 (95% confidence interval (CI): 0.90, 0.90); intraclass correlation coefficient = 0.95 (95% CI: 0.94, 0.95); root mean squared error = 8.24 days) and performed better than all of the alternative methods. REWarDS-estimated days' supply was valid and more accurate than estimates from all other available methods. REWarDS is expected to confer optimal precision in studies measuring warfarin exposure using administrative data.

Trends in the consumption and cost of antiepileptics in Morocco between 2008 and 2018

INTRODUCTION

Epilepsy is one of the most common chronic neurological diseases. In Morocco, it is the second most common reason for consulting a neurologist. Its prevalence was estimated in Casablanca in 1998 at 1.1%. This study was carried out with the aim of evaluating, on the one hand, the consumption of antiepileptics and, on the other hand, the impact of their generic drugs on the pharmaceutical market between 2008 and 2018 in Morocco.

MATERIALS AND METHODS

We used sales data for antiepileptic drugs collected from the Moroccan subsidiary of IQVIA, a multinational healthcare data science company, and we converted them into a defined daily dose (DDD/1000 inhabitants).

RESULTS

The consumption of antiepileptic drugs increased from 442 to 641 DDD/1000 inhabitants between 2008 and 2018, all molecules combined, recording a 45% increase in the period studied. From an economic point of view, the calculation of the average cost of DDD, all molecules combined, gives an average cost of 2.42 dollars/DDD in 2018 versus 3.53 dollars/DDD in 2008 (1 dirham = 0.11 dollar), which corresponds to a decrease of -30%. This is due mainly to the introduction of generic drugs.

CONCLUSION

These results show that while the average cost of a DDD has decreased, the consumption of antiepileptics has increased in Morocco over the years. Several events that have marked the drug market in Morocco have contributed to this trend, including the arrival on the market of several new molecules indicated for the treatment of epilepsy, the decrease in drug prices in 2014 and the policy of promoting generic drugs.

Antidepressants Drug Use during COVID-19 Waves in the Tuscan General Population: An Interrupted Time-Series Analysis

In Italy, during the COVID-19 waves two lockdowns were implemented to prevent virus diffusion in the general population. Data on antidepressant (AD) use in these periods are still scarce. This study aimed at exploring the impact of COVID-19 lockdowns on prevalence and incidence of antidepressant drug use in the general population. A population-based study using the healthcare administrative database of Tuscany was performed. We selected a dynamic cohort of subjects with at least one ADs dispensing from 1 January 2018 to 27 December 2020. The weekly prevalence and incidence of drug use were estimated across different segments: pre-lockdown (1 January 2018–8 March 2020), first lockdown (9 March 2020–15 June 2020), post-first lockdown (16 June 2020–15 November 2020) and second lockdown (16 November 2020–27 December 2020). An interrupted time-series analysis was used to assess the effect of lockdowns on the observed outcomes. Compared to the pre-lockdown we observed an abrupt reduction of ADs incidence (Incidence-Ratio: 0.82; 95% Confidence-Intervals: 0.74–0.91) and a slight weekly decrease of prevalence (Prevalence-Ratio: 0.997; 0.996–0.999). During the post-first lockdown AD use increased, with higher incidence- and similar prevalence values compared with those expected in the absence of the outbreak. This pandemic has impacted AD drug use in the general population with potential rebound effects during the period between waves. This calls for future studies aimed at exploring the mid–long term effects of this phenomenon.

Impact of COVID-19 Lockdown, during the Two Waves, on Drug Use and Emergency Department Access in People with Epilepsy: An Interrupted Time-Series Analysis

BACKGROUND

In 2020, during the COVID-19 pandemic, Italy implemented two national lockdowns aimed at reducing virus transmission. We assessed whether these lockdowns affected anti-seizure medication (ASM) use and epilepsy-related access to emergency departments (ED) in the general population.

METHODS

We performed a population-based study using the healthcare administrative database of Tuscany. We defined the weekly time series of prevalence and incidence of ASM, along with the incidence of epilepsy-related ED access from 1 January 2018 to 27 December 2020 in the general population. An interrupted time-series analysis was used to assess the effect of lockdowns on the observed outcomes.

RESULTS

Compared to pre-lockdown, we observed a relevant reduction of ASM incidence (0.65; 95% Confidence Intervals: 0.59-0.72) and ED access (0.72; 0.64-0.82), and a slight decrease of ASM prevalence (0.95; 0.94-0.96). During the post-lockdown the ASM incidence reported higher values compared to pre-lockdown, whereas ASM prevalence and ED access remained lower. Results also indicate a lower impact of the second lockdown for both ASM prevalence (0.97; 0.96-0.98) and incidence (0.89; 0.80-0.99).

CONCLUSION

The lockdowns implemented during the COVID-19 outbreaks significantly affected ASM use and epilepsy-related ED access. The potential consequences of these phenomenon are still unknown, although an increased incidence of epilepsy-related symptoms after the first lockdown has been observed. These findings emphasize the need of ensuring continuous care of epileptic patients in stressful conditions such as the COVID-19 pandemic.

Pharmacological and epidemiological considerations while constructing treatment episodes using observational data: A simulation study

BACKGROUND

The permissible gap method is an extensively used approach for defining episodes of continuous treatment use in pharmacoepidemiology. This method uses the amount of drug redeemed, when available, and researcher-defined temporal gaps to fill the interval between the calculated end of coverage of a redeemed prescription and the date of redemption of the next prescription in the same treatment episode. The final scope is defining periods of continuous use of medications. There are strong pharmacological and epidemiological arguments for adding the gap at the end of each treatment episode. However, the evidence is scarce on the impact that such a practice has on measures of association. This study aims to compare the impact of adding or not adding the researcher-defined gap time to the end of a treatment episode on the incidence of drug discontinuation and the incidence rate for a simulated outcome that occurred during an observational window. Additionally, the study aims at assessing the magnitude of misclassification of exposure time between the two methods.

METHODS

A simulated dataset of 100 patients available in the R package AdhereR that contains 1080 redeemed prescriptions was used. A gap time of 90 days was used for constructing treatment episodes in an observational window of 365 days following the first redeemed prescription. Two approaches were used for defining treatment episodes that were named "gap+" and "gap-" and that respectively add and did not add the gap time at the end of a treatment episode. An outcome was simulated by using an exponential baseline hazard function with scale parameter λ = 0.5 and censoring at time t = 365 days. The incidence rate ratio for the simulated outcome between the two approaches was computed.

RESULTS

The 100 patients were followed for a median time of 183 days (interquartile range, IQR 50-365 days) and a median time of 273 days (IQR 140-365 days), respectively using "gap-" and "gap+". During the first 100 days of the follow-up period, none of the patients was found to discontinue the treatment with the method "gap+" while 38 patients discontinued using the method "gap-". The approach "gap+" exerted a higher incidence rate for the simulated outcome among the exposed (0.98 events/person-years) when compared to the "gap-" (0.82 events/person-years) during defined periods of continuous treatment use. When comparing the two approaches and using the method "gap-" as the reference group, the incidence rate ratio for the simulated outcome was 1.20 (95% confidence interval: CI 0.72-2.02) among the exposed.

CONCLUSIONS

This study showed that not adding the gap at the end of the treatment episodes leads to an overestimation of drug discontinuation, particularly at the beginning of the observational window, and an underestimation of the incidence rate of a hypothetical outcome during the period of exposure to the medication.

Comparison of surveys and use records for quantifying medically important antimicrobial use in 18 U.S. Beef Feedyards

The objective of this study was to evaluate agreement between medically important antimicrobial use metrics derived from in-person surveys of feedyard management as opposed to metrics derived from production unit-level antimicrobial use records. Survey respondents were asked to estimate values which would allow calculation of the metrics of regimens per animal year (Reg/AY) and milligrams of antimicrobial per kilogram of liveweight sold (mg/kg-LW). At the study level, values were calculated by antimicrobial class within the use categories of in-feed use, control of bovine respiratory disease (BRD) and individual animal treatment. At the feedyard level, values were calculated by total overall use and total use within use category. Feedyard level correlation coefficients between survey and record values for total use were 0.76 (p = .0004) and 0.73 (p = .0009) for Reg/AY and mg/kg-LW, respectively. Correlation coefficients for use category within metric ranged from 0.25 (p = .3224) to 0.65 (p = .0061). Comparing feedyard level survey and record values for total Reg/AY and mg/kg-LW using a Wilcoxon signed-rank test resulted in p-values (95% CI) of 0.3247 (-1.06, 0.25) and 0.7019 (-14.49, 10.387), respectively. Evaluation of comparative rankings as total use by metric indicated that for Reg/AY, only two of the five top-ranked feedyards were consistent between the two data sources. The relationship for mg/kg-LW demonstrated the lowest two and highest three values were consistent between sources; however, the ranking similarities appear to markedly decline in the middle ranks. This report demonstrates that survey-based antimicrobial use data may closely reflect summary values determined from records across multiple beef feedyards. However, individual feedyard relationships between their record and survey values vary widely and ranking by survey may lead to different conclusions as to highest and lowest use than ranking by data collected from use records.

Antimicrobial Usage Among Different Age Categories and Herd Sizes in Swiss Farrow-to-Finish Farms

In the Swiss pig sector, the usage of antimicrobials has been recorded, evaluated and systematically reduced on a voluntary basis since 2015. This monitoring has been carried out using various methods thereby enabling continuous national scrutiny as well as international comparisons. To gain a better understanding of the dynamics of the antimicrobial usage on Swiss farms, consumption data of farrow-to-finish farms were analyzed for (i) the within-herd relationships among different age categories and (ii) the influence of the herd size. The data were collected on 71 farms for the year 2017, encompassing the amount of active ingredients and number of defined daily doses Switzerland (nDDDch) in total, and stratified for the different age categories of piglets, weaners, fattening pigs, and sows. The differences in nDDDch per animal among the age categories were determined by a Wilcoxon test and subsequent post-hoc analysis according to Bonferroni. The within-herd relationship among the individual age categories as well as the influence of the herd size on nDDDch per animal measured as kept sows were analyzed by simple linear regression. The evaluation of the treatment days showed that 50% of the nDDDch were used in piglets, 44% for weaners, and 3% each for fattening pigs and sows. Compared to the other age categories, the examination of the number of nDDDch per animal showed a significantly higher number for sows, whereas for fattening pigs the number was significantly lower (P < 0.01). The farm-based analysis using linear regression showed a relationship between antimicrobial usage in sows and piglets (P < 0.001; adj. R² = 0.19). Similarly, a significant relationship between larger herd size and increased antimicrobial usage was observed (P = 0.02; adj. R² = 0.06). The present study provides an insight into the antimicrobial treatment dynamics of farrow-to-finish farms. In particular, the age categories piglets and sows—with their higher number of treatment days in total or per animal—are of interest regarding the potential reduction in antimicrobial usage. Likewise, larger farms with higher management requirements were found to be of particular importance for the reduction of antimicrobial usage. Monitoring programs should therefore evaluate different age categories separately to identify problems for individual farms.

Antibiotic consumption study in two hospitals in Asmara from 2014 to 2018 using WHO's defined daily dose (DDD) methodology

This study compares the antibiotic consumption rates over a period of five years in two hospitals in Eritrea, Orotta National Referral and Teaching Hospital (ONRTH) and Hazhaz Zonal Referral Hospital (HZRH). Antibiotic consumption is an important parameter in the study of antibiotic use. However, no published data on consumption rates exist for these two hospitals, thus the aim of the study is to measure and compare a five year antibiotic consumption trends of the two hospitals' medical wards using Defined Daily Dose per 100 bed-days (DDD/100-BD). Antibiotics dispensed from January 2014 to December 2018 were considered. Non-parametric Pearson's correlation coefficient was used for comparison of consumption, while non-parametric Friedman's test measured annual rates. The total antibiotic consumption in the HZRH was almost double that of ONRTH. The analysis showed that antibiotic consumption in ONRTH was significantly decreased from 2014 to 2018 while there was no significant difference in consumption in HZRH. Benzyl penicillin was the most consumed antibiotic in HZRH and ONRTH throughout the study period at 87.8DDD/100-BD and 35.4 DDD/100-BD respectively. Ceftriaxone and ciprofloxacin were among the most commonly consumed antibiotics in both hospitals. Establishment of Antibiotic stewardship program would benefit both hospitals greatly, and further studies need to be done to establish the national antibiotic consumption baseline.

Association between the cumulative exposure to bisphosphonates and hospitalization for atherosclerotic cardiovascular events: A population-based study

BACKGROUND AND AIMS

Although bisphosphonates have been suggested to protect against atherosclerotic cardiovascular (CV) events, evidence is still conflicting. We aimed at investigating the effect of bisphosphonates on hospitalizations for atherosclerotic CV events.

METHODS

We carried out a retrospective cohort study selecting subjects aged>40 years, incident users of bisphosphonates. Exposure to bisphosphonates was characterized based on cumulative doses (proportion of days covered, PDC). Treatment's adherence was classified as low (PDC≤40%), intermediate (PDC 41%-80%), or high (PDC>80%). A multivariate Cox model was fitted to estimate the association between cumulative time-dependent exposure to bisphosphonates and hospitalization for atherosclerotic CV events (hazard ratio [HR] and 95% confidence interval).

RESULTS

Among 82,704 new bisphosphonates users (females 87.0%, mean age 70.7 ± 10.6 years), 16.1% had a CV hospitalization during a mean follow-up of 6.5 + 2.6 years. Compared with individuals with PDC ≤40%, those exposed for 41-80% or more than 80% showed HRs of CV hospitalization of 0.95 [0.91-0.99] and 0.75 [0.71-0.81], respectively. In the sub-analysis by type of event, a PDC >80% was associated with a reduced incidence for both coronary and cerebrovascular events (HRs 0.75 [0.68-0.83] and 0.76 [0.70-0.83], respectively). The protective effect was confirmed in stratified analyses by sex and age classes, and in those performed at 1 and 3 years of follow-up.

CONCLUSIONS

Strict adherence to bisphosphonate treatment was associated with a better CV outcome. Although further studies to investigate possible mechanisms are warranted, bisphosphonates could be considered as having a potential CV benefit beyond the effect on bones.

Low adherence to statin treatment during the 1st year after an acute myocardial infarction is associated with increased 2nd-year mortality risk-an inverse probability of treatment weighted study on 54 872 patients

Aims

Experiencing an acute myocardial infarction (AMI) is a life-threatening event and use of statins can reduce the probability of recurrence and improve long-term survival. However, the effectiveness of statins in the real-world setting may be lower than the reported efficacy in randomized clinical trials. Therefore, we aimed to investigate whether low statin treatment adherence during the year following an AMI episode is associated with increased 2nd-year mortality.

Methods and results

We analysed all 54 872 AMI patients aged ≥45 years, admitted to Swedish hospitals between 2010 and 2012, and who survive at least 1 year after the AMI episode. We defined low adherence as a medication possession ratio <50% or non-use of statins. Applying inverse probability of treatment weighting (IPTW), we investigated the association between low adherence and all-cause, cardiovascular disease (CVD), and non-CVD mortality during the 2nd year. Overall, 20% of the patients had low adherence during the 1st year and 8% died during the 2nd year. In the IPTW analysis, low adherence was associated with an increased risk of all-cause [absolute risk difference (ARD) = 0.048, number needed to harm (NNH) = 21, relative risk (RR) = 1.71], CVD (ARD = 0.035, NNH = 29, RR = 1.62), and non-CVD mortality (ARD = 0.013, NNH = 77, RR = 2.17).

Conclusion

In the real-world setting, low statin adherence during the 1st year after an AMI episode is associated with increased mortality during the 2nd year. Our results reaffirm the importance of achieving a high adherence to statin treatment after suffering from an AMI.

Methods for constructing treatment episodes and impact on exposure-outcome associations

PURPOSE

To assess the impact on exposure time and outcome misclassifications, and consequent impact on exposure-outcome associations from treatment episode construction. We investigated the dosage assumptions of 1 unit per day, and 1 DDD per day, versus actual prescribed dosage under different handling of gaps and overlaps of prescriptions.

METHODS

Data on mirtazapine and citalopram exposure (years 2006-2014) from the Swedish Prescribed Drug register were used. Via a within individuals design we compared method A, based on actual dosage, with methods B and C based on 1 unit of drug per day and 1 DDD per day assumptions, respectively, including consideration of gaps and overlaps. Four outcomes were used, hospitalizations and outpatient visits for all and for psychiatric causes.

RESULTS

Relative to method A, both alternative methods lead to misclassification of exposure time. With regard to outcome misclassifications, method B overestimates the effect of the exposure on the outcome in 77% and 100% of exposure definition comparisons for mirtazapine and citalopram respectively, while 23% of the comparisons for mirtazapine results in underestimation of exposure-outcome associations. Conversely, treatment episodes based on DDD (method C) result in underestimation of the exposure-outcome association in 100% and 87.5% of exposure definition comparisons for mirtazapine and citalopram respectively, while 12.5% of the comparisons for citalopram results in overestimation of the exposure-outcome associations.

CONCLUSIONS

The study provides results that have consistent clinical relevance. We have showed that a non-accurate construction of exposure time may lead to errors on outcome detection during exposed time, and consequently affect conclusions on safety or efficacy profile of a treatment.

Urate-lowering treatment and risk of total joint replacement in patients with gout

Objectives

To examine whether gout is an independent risk factor for total joint replacement (TJR) and whether urate-lowering treatment (ULT) reduces this risk.

Methods

Using the Taiwan National Health Insurance database and the UK Clinical Practice Research Datalink, 74 560 Taiwan patients and 34 505 UK patients with incident gout were identified and age and sex matched to people without gout. Cox proportional hazards models and condition logistic regression were used to examine the risk of TJR in gout patients and the association between cumulative defined daily dose (cDDD) of ULT and TJR.

Results

The prevalence rates of TJR in the patients at the time of diagnosis of gout and in people without gout were 1.16% vs 0.82% in Taiwan and 2.61% vs 1.76% in the UK. After a gout diagnosis, the incidence of TJR was higher in the patients with gout compared with those without (3.23 vs 1.91 cases/1000 person-years in Taiwan and 6.87 vs 4.61 cases/1000 person-years in the UK), with adjusted HRs of 1.56 (95% CI 1.45, 1.68) in Taiwan and 1.14 (1.05, 1.22) in the UK. Compared with patients with gout with <28 cDDD ULT, the adjusted ORs for TJR were 0.89 (95% CI 0.77, 1.03) for 28-90 cDDD, 1.03 (0.85, 1.24) for 90-180 cDDD and 1.12 (0.94, 1.34) for >180 cDDD ULT in Taiwan. In the UK, the respective ORs were 1.09 (0.83, 1.42), 0.93 (0.68, 1.27) and 1.08 (0.94, 1.24).

Conclusion

This population-based study provides evidence from two nation populations that gout confers significant TJR risk, which was not reduced by current ULT.

Effect of Improving Volume Overload on Home Blood Pressure Variability in Hemodialysis Patients

Blood pressure variability is an independent predictor of adverse clinical events in hemodialysis patients. Volume overload is one of the most important factors affecting blood pressure homeostasis. In the present study, we explored the effects of dry weight reduction on home blood pressure variability in volume overload hemodialysis patients. Hemodialysis patients with volume overload had their dry weight gradually decreased under the guidance of bioimpedance methods, which was represented by calf-bioimpedance ratio (Calf-BR). Home blood pressure was measured on waking up and at bedtime for 1 week at baseline and at the end of the two-month study. Coefficient of variation was used to define home blood pressure variability. Thirty-eight hemodialysis patients had their dry weight significantly decreased from 60.7 ± 11.3 to 59.6 ± 10.7 kg (P = 0.003) accompanied with a significant reduction in calf-BR (0.828 ± 0.023 vs. 0.786 ± 0.020, P<0.001). The systolic and diastolic blood pressure decreased significantly. Moreover, the whole-day, morning, and evening systolic blood pressure variability gradually and significantly decreased by the end of the study (5.6 ± 2.1% versus 4.0 ± 1.7%, P<0.001; 7.7 ± 3.5% vs. 6.3 ± 2.7%, P = 0.005; 7.5 ± 2.8% vs. 5.9 ± 2.3%, P = 0.002, respectively). Diastolic blood pressure variability parameters were unchanged. The interdialytic weight gain and the incidence of adverse events were similar throughout the study period. Gradual dry weight reduction by bioimpedance methods improved home blood pressure variability in hemodialysis patients with chronic fluid overload.

Antimicrobial Drug Consumption on Swiss Pig Farms: A Comparison of Swiss and European Defined Daily and Course Doses in the Field

Defined Daily Doses (DDD) and Defined Course Doses (DCD) have been established in both human and veterinary medicine in order to standardize the measurement of treatments in a population. In 2016 the European Medicines Agency published average defined daily dose (DDDvet) and defined course dose (DCDvet) values for antimicrobial agents used in livestock production. Similarly, national defined doses (DDDch and DCDch) for the pig sector in Switzerland have recently been determined. The aim of this study was to compare the outcome of calculating antimicrobial consumption based on either DDDvet/DCDvet or DDDch/DCDch. Data from 227 Swiss pig farms describing antimicrobial use in 2015 was collected. The numbers of treatment days and treatments were calculated using DDDvet/DCDvet and DDDch/DCDch respectively, for each farm in total and for different antimicrobial classes. Associations between calculated numbers of DDDvet/DCDvet and DDDch/DCDch on farm level were investigated. In addition, differences concerning antimicrobial use were investigated between different production types of farms (piglet-producer, finishing farm or farrow-to-finishing farm). Using DDDch/DCDch values we calculated 1,805,494 treatment days and 433,678 treatments compared to 1,456,771 treatment days (19% ratio) and 303,913 treatments (30% ratio) based on DDDvet/DCDvet. Penicillins (21.4/26.6%), polypeptides (18.6/27.6%) and fluoroquinolones (9.5/8.8%) were the most frequently used classes of antimicrobials based on calculation using both DDDch and DDDvet. Similar findings were observed for complete treatments (DCDch/vet) (penicillins: 52.8/39.6%; polypeptides: 7.8/14.2%; fluoroquinolones: 13.2/12.9%). The number of treatment days or treatments per farm was higher for piglet-producers and farrow-to-finishing farms compared to finisher farms regardless of whether Swiss or European DDD or DCD values were used for the calculation (each P < 0.001). Similar results for antimicrobial use (AMU) obtained at farm level were observed when calculated either by Swiss or European definitions. Nevertheless, marked differences could be observed in the assessment of the use of specific antimicrobial classes in the field based on DDDvet/DCDvet compared to DDDch/DCDch.

Monitoring Antimicrobial Drug Usage in Animals: Methods and Applications

Monitoring antimicrobial drug usage in animals at the national and international levels is important for identification and tracking if and how often quantities are used. This information can be used for many purposes, including raising awareness, comparing use patterns across countries, identifying trends over time, integrating with antimicrobial resistance data, conducting risk assessment, and evaluating the effectiveness of measures to manage antimicrobial usage. The goal of this article is to describe how monitoring systems for antimicrobial drug usage in animals are set up and conducted, using examples from specific countries as well as international efforts. Several key figures and variables are used to describe and evaluate antimicrobial consumption in animals, including the amount in kilograms of active ingredient, standardized units (e.g., number of defined daily dose animals, DDDAs) and number of treatments (e.g., number of used daily doses, UDDA). Data can be collected from a variety of sources including pharmaceutical sales, pharmacy dispensing, veterinary prescriptions, and farm records. In many countries, data analysis and reporting at the national level provide statistics on overall quantities used in animals, in some cases by animal species. Antimicrobial consumption data should be contrasted to the respective animal population, for example, the weight of different categories of livestock and slaughtered animals. Several countries have established antimicrobial usage monitoring systems. Most report overall sales data, but some provide usage data to the levels of animal species and production type. At the international level, several organizations (e.g., European Union, World Organization for Animal Health, World Health Organization) have initiatives to support the development of antimicrobial consumption data collection and reporting. However, these initiatives are ongoing and so far lack harmonization, which will be the biggest challenge for the future.

Translating Benzodiazepine Utilization Data into Meaningful Population Exposure: Integration of Two Metrics for Improved Reporting

Drug utilization research on benzodiazepines remains important for measuring trends in consumption within and across borders over time for the sake of monitoring prescribing patterns and identifying potential population safety concerns. The defined daily dose (DDD) system by the World Health Organization (WHO) remains the internationally accepted standard for measuring drug consumption; however, beyond consumption, DDD-based results are difficult to interpret when individual agents are compared with one another or are pooled into a total class-based estimate. The diazepam milligram equivalent (DME) system provides approximate conversions between benzodiazepines and Z-drugs (i.e. zopiclone, zolpidem, zaleplon) based on their pharmacologic potency. Despite this, conversion of total dispensed benzodiazepine quantities into DME values retains diazepam milligrams as the total unit of measurement, which is also impractical for population-level interpretation. In this paper, we propose the use of an integrated DME-DDD metric to obviate the limitations encountered when the component metrics are used in isolation. Through a case example, we demonstrate significant change in results between the DDD and DME-DDD method. Unlike the DDD method, the integrated DME-DDD metric offers estimation of population pharmacologic exposure, and enables superior interpretation of drug utilization results, especially for drug class summary reporting.

Methods for time-varying exposure related problems in pharmacoepidemiology: An overview

Purpose

Lack of control for time‐varying exposures can lead to substantial bias in estimates of treatment effects. The aim of this study is to provide an overview and guidance on some of the available methodologies used to address problems related to time‐varying exposure and confounding in pharmacoepidemiology and other observational studies. The methods are explored from a conceptual rather than an analytical perspective.

Methods

The methods described in this study have been identified exploring the literature concerning to the time‐varying exposure concept and basing the search on four fundamental pharmacoepidemiological problems, construction of treatment episodes, time‐varying confounders, cumulative exposure and latency, and treatment switching.

Results

A correct treatment episodes construction is fundamental to avoid bias in treatment effect estimates. Several methods exist to address time‐varying covariates, but the complexity of the most advanced approaches—eg, marginal structural models or structural nested failure time models—and the lack of user‐friendly statistical packages have prevented broader adoption of these methods. Consequently, simpler methods are most commonly used, including, for example, methods without any adjustment strategy and models with time‐varying covariates. The magnitude of exposure needs to be considered and properly modelled.

Conclusions

Further research on the application and implementation of the most complex methods is needed. Because different methods can lead to substantial differences in the treatment effect estimates, the application of several methods and comparison of the results is recommended. Treatment episodes estimation and exposure quantification are key parts in the estimation of treatment effects or associations of interest.

Trends in antibiotic prescribing by dental practitioners in Germany

PURPOSE

To analyze the structure of antibiotic prescriptions by dentists in Germany during a time-period of four years in relation to medical antibiotic prescriptions.

MATERIALS AND METHODS

We collected nationwide data from all statutory health insurances on dental prescriptions of systemic antibiotics from 2012 to 2015. The annual reports of the "Research Institute for Local Health Care Systems" (WIdO, Berlin) provided the basis for this longitudinal data base analysis. The types of antibiotics, the number of prescriptions and the prescribed 'defined daily doses' (DDD) were analyzed. The results were compared to antibiotic prescriptions of German physicians.

RESULTS

An average of 8.8% per year of all antibiotic prescriptions is issued by dentists. The mostly prescribed antibiotic is amoxicillin. The share of amoxicillin on all dental prescriptions increased from 35.6% in 2012 to 45.8% in 2015 (p < 0.01). About three-quarters of all dentally prescribed DDD can be attributed to amoxicillin and clindamycin. On the part of the physicians the proportion of clindamycin is 18 fold lower than in the dental field.

CONCLUSIONS

Dental and medical antibiotic prescriptions in Germany show statistically significant differences regarding the shares of the prescribed antibiotics. In an international comparison the high proportion of Clindamycin in Germany is noticeable.

Use of antipsychotics, benzodiazepine derivatives, and dementia medication among older people with intellectual disability and/or autism spectrum disorder and dementia

BACKGROUND

Although people with intellectual disability (ID) and people with dementia have high drug prescription rates, there is a lack of studies investigating drug use among those with concurrent diagnoses of ID and dementia.

AIM

To investigate the use of antipsychotics, benzodiazepine derivatives, and drugs recommended for dementia treatment (anticholinesterases [AChEIs] and memantine) among people with ID and dementia.

METHODS AND PROCEDURES

Having received support available for people with ID and/or autism spectrum disorder (ASD) was used as a proxy for ID. The ID cohort consisted of 7936 individuals, aged at least 55 years in 2012, and the referent cohort of age- and sex-matched people from the general population (gPop). People with a specialists' diagnosis of dementia during 2002-2012 were identified (ID, n=180; gPop, n=67), and data on prescription of the investigated drugs during the period 2006-2012 were collected.

OUTCOME AND RESULTS

People with ID/ASD and dementia were more likely than people with ID/ASD but without dementia to be prescribed antipsychotics (50% vs 39% over the study period; odds ratio (OR) 1.85, 95% confidence interval 1.13-30.3) and benzodiazepine derivatives (55% vs 36%; OR 2.42, 1.48-3.98). They were also more likely than people with dementia from the general population to be prescribed antipsychotics (50% vs 25%; OR 3.18, 1.59-6.34), but less likely to be prescribed AChEIs (28% vs 45%; OR 0.32, 0.16-0.64).

Cabergoline for Cushing's disease: a large retrospective multicenter study

OBJECTIVE

The efficacy of cabergoline in Cushing's disease (CD) is controversial. The aim of this study was to assess the efficacy and tolerability of cabergoline in a large contemporary cohort of patients with CD.

DESIGN

We conducted a retrospective multicenter study from thirteen French and Belgian university hospitals.

METHODS

Sixty-two patients with CD received cabergoline monotherapy or add-on therapy. Symptom score, biological markers of hypercortisolism and adverse effects were recorded.

RESULTS

Twenty-one (40%) of 53 patients who received cabergoline monotherapy had normal urinary free cortisol (UFC) values within 12 months (complete responders), and five of these patients developed corticotropic insufficiency. The fall in UFC was associated with significant reductions in midnight cortisol and plasma ACTH, and with clinical improvement. Compared to other patients, complete responders had similar median baseline UFC (2.0 vs 2.5xULN) and plasma prolactin concentrations but received lower doses of cabergoline (1.5 vs 3.5 mg/week, P < 0.05). During long-term treatment (>12 months), cabergoline was withdrawn in 28% of complete responders because of treatment escape or intolerance. Overall, sustained control of hypercortisolism was obtained in 23% of patients for 32.5 months (19-105). Nine patients on steroidogenesis inhibitors received cabergoline add-on therapy for 19 months (1-240). Hypercortisolism was controlled in 56% of these patients during the first year of treatment with cabergoline at 1.0 mg/week (0.5-3.5).

CONCLUSIONS

About 20-25% of CD patients are good responders to cabergoline therapy allowing long-term control of hypercortisolism at relatively low dosages and with acceptable tolerability. No single parameter, including the baseline UFC and prolactin levels, predicted the response to cabergoline.

Seasonality of antibiotic prescriptions for outpatients and resistance genes in sewers and wastewater treatment plant outflow

To test the hypothesis of a seasonal relationship of antibiotic prescriptions for outpatients and the abundance of antibiotic resistance genes (ARGs) in the wastewater, we investigated the distribution of prescriptions and different ARGs in the Dresden sewer system and wastewater treatment plant during a two-year sampling campaign. Based on quantitative PCR (qPCR), our results show a clear seasonal pattern for relative ARGs abundances. The higher ARGs levels in autumn and winter coincide with the higher rates of overall antibiotic prescriptions. While no significant differences of relative abundances were observed before and after the wastewater treatment for most of the relative ARGs, the treatment clearly influenced the microbial community composition and abundance. This indicates that the ARGs are probably not part of the dominant bacterial taxa, which are mainly influenced by the wastewater treatment processes, or that plasmid carrying bacteria remain constant, while plasmid free bacteria decrease. An exception was vancomycin (vanA), showing higher relative abundance in treated wastewater. It is likely that a positive selection or community changes during wastewater treatment lead to an enrichment of vanA. Our results demonstrate that in a medium-term study the combination of qPCR and next generation sequencing corroborated by drug-related health data is a suitable approach to characterize seasonal changes of ARGs in wastewater and treated wastewater.

The Use of Benzodiazepine Receptor Agonists and Risk of Respiratory Failure in Patients with Chronic Obstructive Pulmonary Disease: A Nationwide Population-Based Case-Control Study

STUDY OBJECTIVES

Insomnia is prevalent in patients with chronic obstructive pulmonary disease (COPD), and benzodiazepine receptor agonists (BZRAs) are the most commonly used drugs despite their adverse effects on respiratory function. The aim of this study was to investigate whether the use of BZRAs was associated with an increased risk of respiratory failure (RF) in COPD patients.

DESIGN

Matched case-control study.

SETTING

National Health Insurance Research Database (NHIRD) in Taiwan.

PARTICIPANTS

The case group consisted of 2,434 COPD patients with RF, and the control group consisted of 2,434 COPD patients without RF, matched for age, sex, and date of enrollment.

MEASUREMENTS AND RESULTS

Exposure to BZRAs during the 180-day period preceding the index date was analyzed and compared in the case and control groups. Conditional logistic regression was performed, and the use of BZRAs was associated with an increased risk of RF (adjusted odds ratio [aOR] 1.56, 95% confidence interval [CI] 1.14-2.13). In subgroup analysis, we found that the benzodiazepine (BZD) users had a higher risk of RF (aOR 1.58, 95% CI 1.14-2.20), whereas the risk in non-benzodiazepine (non-BZD) users was insignificant (aOR 0.85, 95% CI 0.51-1.44). A greater than 2-fold increase in risk was found in those who received two or more kinds of BZRAs and those using a combination of BZD and non-BZD medications.

CONCLUSIONS

The use of benzodiazepine receptor agonists was a significant risk factor for respiratory failure in patients with chronic obstructive pulmonary disease (COPD). Compared to benzodiazepine, the prescription of non-benzodiazepine may be safer for the management of insomnia in COPD patients.

Measuring drug exposure: concordance between defined daily dose and days' supply depended on drug class

OBJECTIVES

To determine the concordance between two methods to measure drug exposure duration from pharmacy claim data.

STUDY DESIGN AND SETTING

We conducted a cohort study using 2002-2007 US Medicaid data. Initiators of eight drug groups were identified: statins, metformin, atypical antipsychotics, warfarin, proton pump inhibitors (PPIs), angiotensin-converting enzyme (ACE) inhibitors, nonsteroidal anti-inflammatory drugs (ns-NSAIDs), and coxibs. For each patient, we calculated two measures of exposure duration using (1) observed days' supply available in US pharmacy claims and (2) the World Health Organisation's Defined Daily Dose (DDD) methodology. We used Wilcoxon signed rank tests to compare medians and Spearman correlations to assess correlation between the two measures.

RESULTS

Cohort sizes ranged from 143,885 warfarin users to >3,000,000 ns-NSAID users. Similar median exposure durations were observed for ACE inhibitors (70 days vs.75 days), PPIs (44 days vs. 45 days), and coxibs (44 days vs. 45 days). The DDD method overestimated exposure duration for ns-NSAIDs and underestimated for the remaining drug groups, relative to days' supply. Spearman correlation coefficients ranged from 0.2 to 0.8.

CONCLUSION

Using DDDs to estimate drug exposure duration can result in misclassification. The magnitude of this misclassification might depend on doses used which can vary according to factors such as local prescribing practices, renal function, and age.

Antifungal susceptibilities of bloodstream isolates of Candida species from nine hospitals in Korea: application of new antifungal breakpoints and relationship to antifungal usage

We applied the new clinical breakpoints (CBPs) of the Clinical and Laboratory Standards Institute (CLSI) to a multicenter study to determine the antifungal susceptibility of bloodstream infection (BSI) isolates of Candida species in Korea, and determined the relationship between the frequency of antifungal-resistant Candida BSI isolates and antifungal use at hospitals. Four hundred and fifty BSI isolates of Candida species were collected over a 1-year period in 2011 from nine hospitals. The susceptibilities of the isolates to four antifungal agents were determined using the CLSI M27 broth microdilution method. By applying the species-specific CBPs, non-susceptibility to fluconazole was found in 16.4% (70/428) of isolates, comprising 2.6% resistant and 13.8% susceptible-dose dependent isolates. However, non-susceptibility to voriconazole, caspofungin, or micafungin was found in 0% (0/370), 0% (0/437), or 0.5% (2/437) of the Candida BSI isolates, respectively. Of the 450 isolates, 72 (16.0%) showed decreased susceptibility to fluconazole [minimum inhibitory concentration (MIC) ≥4 μg/ml]. The total usage of systemic antifungals varied considerably among the hospitals, ranging from 190.0 to 7.7 defined daily dose per 1,000 patient days, and fluconazole was the most commonly prescribed agent (46.3%). By Spearman’s correlation analysis, fluconazole usage did not show a significant correlation with the percentage of fluconazole resistant isolates at hospitals. However, fluconazole usage was significantly correlated with the percentage of fluconazole non-susceptible isolates (r = 0.733; P = 0.025) or the percentage of isolates with decreased susceptibility to fluconazole (MIC ≥4 μg/ml) (r = 0.700; P = 0.036) at hospitals. Our work represents the first South Korean multicenter study demonstrating an association between antifungal use and antifungal resistance among BSI isolates of Candida at hospitals using the new CBPs of the CLSI.

Facility-Level Correlates of Antimicrobial Use in Nursing Homes

We assessed the contribution of facility-Ievel variables to antimicrobial use in a cohort of 50 nursing homes and found that antimicrobial use was significantly correlated with the percentage of nursing home residents with feeding tubes, the number of healthcare aides, and the country of origin of the facility.

Hospital- and patient-related factors associated with differences in hospital antibiotic use: analysis of national surveillance results

Background

Surveillance data of antibiotic use are increasingly being used for benchmarking purposes, but there is a lack of studies dealing with how hospital- and patient-related factors affect antibiotic utilization in hospitals. Our objective was to identify factors that may contribute to differences in antibiotic use.

Methods

Based on pharmacy sales data (2006–2011), use of all antibiotics, all penicillins, and broad-spectrum antibiotics was analysed in 22 Health Enterprises (HEs). Antibiotic utilization was measured in World Health Organisation defined daily doses (DDDs) and hospital-adjusted (ha)DDDs, each related to the number of bed days (BDs) and the number of discharges. For each HE, all clinical specialties were included and the aggregated data at the HE level constituted the basis for the analyses. Fourteen variables potentially associated with the observed antibiotic use – extracted from validated national databases – were examined in 12 multiple linear regression models, with four different measurement units: DDD/100 BDs, DDD/100 discharges, haDDD/100 BDs and haDDD/100 discharges.

Results

Six variables were independently associated with antibiotic use, but with a variable pattern depending on the regression model. High levels of nurse staffing, high proportions of short (<2 days) and long (>10 days) hospital stays, infectious diseases being the main ICD-10 diagnostic codes, and surgical diagnosis-related groups were correlated with a high use of all antibiotics. University affiliated HEs had a lower level of antibiotic utilization than other institutions in eight of the 12 models, and carried a high explanatory strength. The use of broad-spectrum antibiotics correlated strongly with short and long hospital stays. There was a residual variance (30%–50% for all antibiotics; 60%–70% for broad-spectrum antibiotics) that our analysis did not explain.

Conclusions

The factors associated with hospital antibiotic use were mostly non-modifiable. By adjusting for these factors, it will be easier to evaluate and understand observed differences in antibiotic use between hospitals. Consequently, the inter-hospital differences can be more confidently acted upon. The residual variation is presumed to largely reflect prescriber-related factors.

Benzodiazepine-associated hepatic encephalopathy significantly increased healthcare utilization and medical costs of Chinese cirrhotic patients: 7-year experience

BACKGROUND AND OBJECTIVES

In cirrhosis, hypersensitivity to benzodiazepines (BZD) and precipitating hepatic encephalopathy (HE) have been reported. The aim of this study was to evaluate the safety, economic impact and modifiable factors that are associated with the excess risk of BZD-associated HE in cirrhotic patients.

METHODS

Between July 2005 and March 2012, 1,612 Chinese cirrhotic patients with and without using long-t 1/2-BZD or short-t 1/2-BZD were enrolled and followed up for 6 months.

RESULTS

Among BZD users, the per-person HE-related healthcare utilization and medical costs were found to have progressively increased from 2005 to 2012. Cirrhotic BZD users had a higher percentage of smoking, alcohol drinking, simultaneous consumption of non-BZD drugs, and had a higher incidence of non-cirrhotic chronic illness than non-BZD users. Multivariate analysis indicated that hypoalbuminemia (<3 g/dL), long-acting (t 1/2 > 12-h), high-dosage (>1.5 defined daily dose equivalents) and long-duration (>2-months) BZD use, carrier of variant genotypes (AG + GG) of GABRA 1 (rs2290732) and having the wild genotype (TT) of GABRG 2 (rs211037) were significant predictors of the development of BZD-associated HE in cirrhotic patients. Additionally, synergistic effects of the above significant predictors on BZD-associated HE risk could be identified.

CONCLUSIONS

Our study confirms the clinical and economic impact of BZD-associated HE in cirrhotic BZD-users. Accordingly, extra caution is needed when treating cirrhotic BZD users with the above risk factors in order to avoid the BZD-associated HE in cirrhotic patients.

Impact of dry weight determined by calf bioimpedance ratio on carotid stiffness and left ventricular hypertrophy in hemodialysis patients

Our previous study has shown that modification of bioimpedance technique by the measurement of bioimpedance ratio in the calf (calf-BR) was a simple and practical method in assessing fluid status in hemodialysis patients. However, the consequences of periodical dry weight (DW) adjustment under the guidance of calf-BR on target organ damage have not been investigated. One hundred fifteen hemodialysis patients were enrolled in this pilot trial. Patients were divided into bioimpedance group and control group according to their dialysis schedule. In the bioimpedance group, DW was routinely adjusted under the guidance of calf-BR every 3 months. In the control group, the assessment of DW remained a clinical judgment. Carotid stiffness, left ventricular mass index (LVMI), and calf-BR were measured at baseline and at the 12th month in both groups. Home blood pressure (BP) was monitored monthly. Episodes of dialysis-related adverse events were recorded. No significant differences were observed in parameters between the two groups at baseline. Compared with the control group, the bioimpedance group had significantly lower values in terms of the annual averages of systolic home BP (147.4 ± 15.3 mm Hg vs. 152.6 ± 16.9 mm Hg, P = 0.019), carotid stiffness index β (10.7 ± 3.3 vs. 12.2 ± 3.1, P = 0.003), LVMI (155.21 ± 15.64 g/m(2) vs. 165.17 ± 16.76 g/m(2) , P < 0.001), and the percentage of individuals with calf-BR over target range (P = 0.040) at month 12, with less annual averages of antihypertensive medications used and lower frequency of intradialytic hypotension, muscle cramps, or clotted angioaccess. Continued DW control achieved by periodical calf-BR measurement improved arterial stiffness and left ventricular hypertrophy with good tolerability in hemodialysis patients.

Antibiotic prescribing in two private sector hospitals; one teaching and one non-teaching: a cross-sectional study in Ujjain, India

BACKGROUND

The worldwide increase in antibiotic resistant bacteria is of great concern. One of the main causes is antibiotic use which is likely to be high but is poorly described in India. The aim was to analyze and compare antibiotic prescribing for inpatients, in two private sector tertiary care hospitals; one Teaching and one Non-teaching, in Ujjain, India.

METHODS

A cross-sectional study with manual data collection was carried out in 2008. Antibiotic prescribing was recorded for all inpatients throughout their hospital stay. Demographic profile of inpatients and prescribed antibiotics were compared. WHO Anatomical Therapeutic Chemical (ATC) classifications for antibiotics was used and Defined Daily Doses (DDD) were calculated per patient day.

RESULTS

A total of 8385 inpatients were admitted during the study period. In the Teaching hospital (TH) 82% of 3004 and in the Non-teaching hospital (NTH) 79% of 5381 patients were prescribed antibiotics. The most commonly prescribed antibiotic groups were; fluoroquinolones and aminoglycosides in the TH and, 3rd generation cephalosporins and combination of antibiotics in the NTH. Of the prescriptions, 51% in the TH and 87% in the NTH (p<0.001) were for parenteral route administration. Prescribing by trade name was higher in the NTH (96%) compared with the TH (63%, p<0.001).

CONCLUSIONS

The results from both hospitals show extensive antibiotic prescribing. High use of combinations of antibiotics in the NTH might indicate pressure from pharmaceutical companies. There is a need to formulate and implement; based on local prescribing and resistance data; contextually appropriate antibiotic prescribing guidelines and a local antibiotic stewardship program.

Randomized trials in angioplasty and stenting of the renal artery: tabular review of the literature and critical analysis of their results

As the incidence of hypertension (HTN) continues to rise, finding the optimal treatment of this multifactorial disease is critical. Renal artery stenosis (RAS) is a known etiology for HTN and is associated with declining renal function. Other than medications, the original gold standard for treatment of HTN from RAS was with an open surgical revascularization or nephrectomy. Since then, endovascular interventions for RAS have been reported to be technically possible, but their efficacy over medications or surgery has yielded conflicting results in case series and randomized trials. This tabular review summarizes the results of randomized trials that compared the outcomes of endovascular renal artery interventions with nonendovascular techniques (including medical and surgical treatments) for the treatment of HTN and renal dysfunction. Based on these data, the strengths and weaknesses of individual trials are critically analyzed to better define the methods to identify and treat patients with RAS.

Prevalence and risk of polypharmacy among the elderly in an outpatient setting: a retrospective cohort study in the Emilia-Romagna region, Italy

BACKGROUND

Polypharmacy, the simultaneous taking of many medications, has been well documented and is a topic of much concern for those looking to improve the quality of care for the elderly. Elderly patients often develop complicated and multifactorial health states that require extensive pharmacotherapy, leaving this population at risk for exposure to drug-drug interactions and other adverse events. Previous literature supports an association between an increase in the rate of adverse events as the number of drugs taken by a patient increases.

OBJECTIVE

We sought to evaluate the prevalence of polypharmacy, and to determine patient characteristics that are predictive of exposure to polypharmacy, in the elderly population of the Emilia-Romagna region in Italy.

METHODS

We conducted a retrospective cohort study of the 2007 Emilia-Romagna outpatient pharmacy database linked with patient information available from a demographic file of approximately 1 million Emilia-Romagna residents aged ≥65 years. The cohort comprised 887,165 elderly subjects who had at least one prescription filled during the study year. Using the WHO's defined daily dose (DDD) to determine the duration of treatment for a given drug, we defined a polypharmacy episode as overlapping treatment with five or more medications occurring for at least 1 day. The prevalence of polypharmacy was measured together with subject characteristics found to be predictive of polypharmacy exposure.

RESULTS

A total of 349,689 elderly people in the population (39.4%) were exposed to at least one episode of polypharmacy during the study period. The prevalence of polypharmacy substantially increased with age and with a higher number of chronic conditions. Over 35% of those exposed to polypharmacy were exposed for 101 or more days of the year. The top three classes of medications involved in polypharmacy were antithrombotics, peptic ulcer disease and gastro-oesophageal reflux disease agents, and ACE inhibitors. The odds of exposure to polypharmacy were higher for older subjects, males and subjects living in urban areas.

CONCLUSIONS

This study provides evidence that the prevalence of polypharmacy in the elderly in Emilia-Romagna is substantial. Educational programmes should be developed to inform clinicians about the magnitude of the polypharmacy phenomenon and the patient characteristics associated with polypharmacy. Raising physicians' awareness of polypharmacy may help to ensure safe, effective and appropriate use of medication in the elderly.

Impact of antimicrobial stewardship programme changes on unnecessary double anaerobic coverage therapy

BACKGROUND

Concern has been raised over the practice of unnecessary double anaerobic coverage therapy (DACT) in the hospital setting. However, the incidence of and risk factors for unnecessary DACT are not well studied. On 8 September 2008, the antimicrobial stewardship programme (ASP) at our institution was modified such that several antibiotics, including ampicillin/sulbactam and metronidazole, no longer required pre-approval. We anticipated that this change would increase both unnecessary DACT and target antibiotic consumption.

METHODS

A nested case-control study was conducted to determine the cumulative incidence of and risk factors for unnecessary DACT. Cases were subjects who received unnecessary DACT while controls were subjects who did not receive DACT or who received necessary DACT. Segmented regression analysis was subsequently performed to evaluate the impact of ASP changes on unnecessary DACT and consumption of target antibiotics.

RESULTS

From October 2007 to September 2009, the cumulative incidence of unnecessary DACT was 2.3% [95% confidence interval (CI) 1.7-3.1]. Independent risk factors for unnecessary DACT [adjusted odds ratio (95% CI); P value] included hospitalization on a surgical ward [3.51 (1.03-12.02); P = 0.002], hospitalization on an obstetrics and gynaecology ward [9.07 (2.54-32.40); P = 0.002] and underlying metastatic malignancy [3.18 (1.38-7.09); P = 0.006]. The ASP change was associated with an increase in ampicillin/sulbactam and metronidazole consumption. However, there was no significant impact on unnecessary DACT prescribing.

CONCLUSIONS

Although uncommon, unnecessary DACT is more prevalent in specific services. Future qualitative studies focusing on these specific subgroups would be useful in elucidating this problem more clearly. The ASP changes were not associated with increases in unnecessary DACT.

Discrepancies between prescribed and defined daily doses: a matter of patients or drug classes?

Purpose

Defined daily doses (DDD) are used for the measurement of drug utilisation. The aim of the study was to analyse whether differences between DDD and prescribed daily doses (PDD) exist for relevant drug classes such as antihypertensive drugs and, if so, whether they primarily depend on drug classes or patient-related factors.

Methods

Using the data of a large German statutory health insurance scheme, we analysed continuous prescriptions for the following antihypertensive drug classes: thiazide diuretics, beta-blockers, dihydropyridine calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin-II receptor blockers (ARBs). We summed the doses of all dispensed drugs per person during a defined time frame. We calculated the PDD (= total dose divided by the number of days) and expressed them as the PDD:DDD ratio (= amount of DDD per day and person).

Results

During the study period, 149,704 patients continuously received an antihypertensive medication. The average PDD:DDD ratio ranged from 0.84 (beta-blockers) to 1.88 (ARBs) and 2.17 (ACEIs). The average prescribed dosage of each drug class remained unchanged, even if the patients had previously received another antihypertensive drug with another PDD:DDD ratio. For example, if patients were switched from a beta-blocker to an ACEI, the PDD:DDD ratio increased, on average, from 0.79 to 2.17. Vice versa, the ratio decreased for patients with a drug change from an ACEI to a beta-blocker from 2.06 to 0.75.

Conclusions

Even large differences between DDD and PDD seem to be a matter of drug classes and not primarily of patient characteristics.

Effect of benzodiazepine discontinuation on dementia risk

OBJECTIVES

This study aimed to examine whether benzodiazepine (BZD) discontinuation would decrease the risk of dementia.

DESIGN

A population-based nested case-control study of dementia was used.

SETTING

All subjects aged 45 years or older and enrolled in the National Health Insurance Research Database in Taiwan between 1997 and 2007 were randomly selected.

PARTICIPANTS

A total of 8,434 cases had been identified with dementia at least three times in ambulatory claims or with one record in inpatient claims. They were individually matched with two comparison subjects (N = 16,706) by age, gender, and index date.

MEASUREMENTS

The lengths of discontinuation, cumulative BZD dose, and potential confounding factors, including medical and psychiatric disorders, were measured and used for further analysis.

RESULTS

Compared with nonusers, current users had an increased risk of dementia (adjusted odds ratio [aOR] = 2.71; 95% confidence interval [CI], 2.46-2.99). The dementia risk for former users was reduced as the duration of discontinuation lengthened (<1 month aOR = 2.40, 95% CI, 1.98-2.92; 1-3 months aOR = 1.93, 95% CI, 1.67-2.23; 3-6 months aOR = 1.49, 95% CI, 1.28-1.74; 6-12 months aOR = 1.43, 95% CI, 1.25-1.64; 1-2 years aOR = 1.23, 95% CI, 1.09-1.40; 2-3 years aOR = 1.22, 95% CI, 1.06-1.40; and >3 years aOR = 1.08, 95% CI, 0.98-1.20). The decreasing trend was significant (p < 0.001).

CONCLUSION

The risk of dementia was high for current users and decreased as the duration of BZD discontinuation lengthened. Further investigations are needed to replicate this association and explore the underlying mechanism that links long-term BZD use, BZD discontinuation, and the pathogenesis of neurocognitive dysfunction.